Field of the Invention
The present invention relates to a film and a method for manufacturing the same, an optical film, a polarizer-protecting film, a polarizing plate, and an image display device. In more detail, the present invention relates to a film including a cyclic olefin resin and a method for manufacturing the film including the cyclic olefin resin, and an optical film, a polarizer-protecting film, a polarizing plate, and an image display device using the film including the cyclic olefin resin.
Description of the Related Art
In the related art, various films have been used as image display device applications such as a polarizer-protecting film of a liquid crystal display device, and films to which various additives are added are known. In recent years, an image display device which can be used in various environments such as an environment of high humidity has been required, and therefore, such a film of image display device applications has been required to have a high water vapor barrier property such that water does not enter the image display device.
It is known that a film of which a raw material is a cyclic olefin resin has a high water vapor barrier property, however, there is a problem in that the film is too soft to be used as a surface film on the viewing side of the image display device and is likely to be scratched, and therefore, it is necessary to improve surface hardness (refer to JP-A-2005-213365). JP-A-2005-213365 describes that there is a method of adding an inorganic material as a means for improving hardness of the film of which a raw material is a cyclic olefin resin, and when mixing an inorganic filler to the extent of sufficiently improving a pencil hardness, there was a problem that optical performance deterioration such as haze occurs. In contrast, in JP-A-2005-213365, the haze-worsening in a film is suppressed and the hardness is improved by highly dispersing layer silicate into a cyclic olefin film by the desired method.
On the other hand, an example in which the hardness of a film is improved by using a cage-shaped silosesquioxane compound (hereinafter, also referred to as POSS) is known (refer to JP-A-2009-042351 and JP-T-2010-523771). In JP-A-2009-042351, POSS is added to a functional layer provided on a base film to increase the hardness of the functional layer, and thereby, the surface hardness of the entire film is improved. Here, POSS is added into an acrylic resin layer or a urethane resin layer, however, POSS is not added to a cyclic olefin resin layer.
Also in JP-T-2010-523771, POSS and the like are added to a base film formed of polypropylene, polyethylene and other noncyclic polyolefin, POSS and the like are moved on the film surface, and thereby, stability against aging, storage life, hydrophobicity, abrasion tolerance, hardness, and friction of the base film are improved, however, POSS is not added to the base film using a cyclic olefin resin as a material, and there is no suggestion regarding application to a cyclic olefin resin.